How can add parameters to href url when click on tag a?

Question

I want From home page send parameter id to carts page:

This is current code, but it not woking:

<a  href="carts" onclick="addParam();">detail</a>
<script>

     function addParam()
     {
         var url = window.location.href;
         var listId = localStorage.getItem('IDs', '');          
         url=url+ "?id=" +listId;
         window.location.href = url;
     }
</script>

How can add parameters to href url when click on tag a?

Answer 1

Either just override it by grabbing the element's (here done by passing this to the function) href

<a  href="carts" onclick="addParam(this);">detail</a>
<script>

     function addParam(el)
     {
         var listId = localStorage.getItem('IDs', '');          
         window.location.href = el.href + "?id=" +listId;
     }
</script>

Or append it to the element's href

<a  href="carts" onclick="addParam(this);">detail</a>
<script>

     function addParam(el)
     {
         var listId = localStorage.getItem('IDs', '');          
         el.href += "?id=" +listId;
     }
</script>